DE102017214975A1 - Powertrain for fuel cell vehicle - Google Patents

Abstract

The invention relates to a drive train for a fuel cell vehicle and a fuel cell vehicle (1) with such. The drive train comprises an electric motor (31) for driving the vehicle (1); a fuel cell system (10) for generating electrical energy for operating the electric motor (31) having at least one fuel cell (11) and being adapted to be selectively operated with a first fuel or a second fuel; and a tank system (20) having a first tank port (23) for refueling with the first fuel and a second tank port (24) for refueling with the second fuel.

Description

The invention relates to a drive train for a fuel cell vehicle having a fuel cell system having at least one fuel cell and to a tank system having at least one tank. The invention further relates to a corresponding fuel cell vehicle.

Fuel cells use the chemical transformation of a fuel with oxygen to water to generate electrical energy. They have an anode and a cathode which are gas-tightly separated from one another and electrically insulated by a polymer electrolyte membrane or an electrolyte. In operation, the anode is supplied with a fuel, for example hydrogen, and the cathode with an oxygen-containing gas, for example air. At the anode, an electrochemical oxidation of the fuel takes place, for example, to protons H ⁺ with the emission of electrons. The electrons are discharged through an external circuit and flow via an electrical load, such as an electric motor, to the cathode. At the cathode, the reduction of oxygen to O ^{2- takes place} . A mobile ion generated in the fuel cell reactions, for example H ⁺ , H ₃ O ⁺ or O ^2- , diffuses via the electrolyte into the adjacent electrode space. In the case of hydrogen fuel cells, protons are the mobile ions that diffuse to the cathode where they react with the oxygen anions to form water. There are various types of fuel cells known that use different fuels and differ in their structure. For example, polymer electrolyte membrane fuel cells (PEMFC) and phosphoric acid fuel cells (PAFC) use hydrogen, direct methanol fuel cells (DMFC) methanol, and solid oxide fuel cells (SOFC) optionally hydrogen, methanol, carbon monoxide or synthesis gas. In the latter case, the fuel converted in the fuel cell is generally produced by an upstream reformer of hydrocarbons, for example CNG (compressed natural gas).

For automotive applications, the use of PEMFC using pure hydrogen as a primary energy source is currently being pursued. One problem, however, is the inadequately developed hydrogen supply infrastructure.

To solve hybrid strategies for fuel cell vehicles are known, which provide the fuel cell with externally supplied electrical energy. The concepts range from fuel cell full drives to battery-powered vehicles, which are equipped with performance-related small-sized fuel cell systems for extending the range (range extender). In addition, the possibility of a plug-in vehicle with a fuel cell power train with electrical charging connection is known. However, the electrical charging networks are partially not yet developed nationwide.

Furthermore, there are approaches to circumvent the problems of hydrogen and charging network supply by using a SOFC and, for example, CNG as a primary energy source.

DE 10 2008 032 105 A1 describes a drive concept with an internal combustion engine which is operated at low torques with hydrogen and at higher torques with a further fuel, namely a hydrocarbon and / or an alcohol.

Out DE 10 2004 037 851 A1 For example, a vehicle is known which has either an electromotive fuel cell drive or an internal combustion engine drive. The vehicle comprises a tank system with several tanks connected in parallel for storing hydrogen for supplying the fuel cell or natural gas for supplying the internal combustion engine.

The invention has for its object to propose a drive train for a fuel cell vehicle, which solves the problems of the prior art described or at least reduced. In particular, the powertrain should be less dependent on the supply infrastructure of the primary energy sources.

This object is achieved by a drive train and a fuel cell vehicle with the features of the independent claims. Preferred embodiments of the invention will become apparent from the remaining features mentioned in the dependent claims.

The drive train according to the invention comprises an electric motor for driving the vehicle; a fuel cell system for generating electrical energy for operating the electric motor having at least one fuel cell and configured to be selectively operated with a first fuel or a second fuel; and a tank system having a first tank port for refueling with the first fuel and a second tank port for refueling with the second fuel.

The invention thus provides a drive train for a fuel cell vehicle which can be operated with at least two different fuels. For example, as fuels hydrogen H ₂ and CNG (compressed natural gas) in question. Of the Drive train according to the invention thus has an improved flexibility with regard to the fuel to be refueled and thus also with regard to the filling station to be claimed. Thus, the corresponding fuel cell vehicle also becomes attractive in regions in which, for example, the hydrogen supply network is poorly developed.

In embodiments of the invention, the tank system has a tank for selectively receiving the first and second fuels. The first and the second tank connection are assigned to this tank. In this embodiment, therefore, one and the same tank has two tank connections, which allow the refueling with one of the two fuels. The advantage here is the smaller space requirement compared to a system with multiple tanks.

In an alternative embodiment, the tank system of the drive train has a first tank for receiving the first fuel and a second tank for receiving the second fuel. Here the first tank connection is assigned to the first tank and the second tank connection to the second tank. Equipped with two tanks designed for different fuels makes it possible to fill both tanks with the availability of both fuels, which increases the range of the vehicle or allows the less available or more expensive fuel to be carried as a reserve.

In further embodiments of the invention, the fuel cell system has a first fuel cell operable with the first fuel and a second fuel cell operable with a second fuel cell. For example, the first fuel cell may be a fuel cell operable by pure hydrogen H ₂ , in particular a polymer electrolyte membrane fuel cell (PEMFC) or phosphorus fuel cell (PAFC), and in the second fuel cell a direct methanol fuel cell (DMFC), which is operated with methanol, or a solid oxide fuel cell (SOFC), which is operated with compressed natural gas (CNG).

In a preferred embodiment, the fuel cell system has only a single fuel cell, which can be operated either with the first or with the second fuel. Here, for example, SOFC systems are used which can be operated either with pure hydrogen or with CNG.

In the case of a design with two fuel cells may also be provided that the tank system has a (single) tank for selectively receiving the first or the second fuel and the first and the second tank port associated with this tank, the tank with either the first or the second fuel cell is fluid-conducting connectable.

In advantageous embodiments of the invention, the drive train further comprises a first communication device associated with the first tank port and a second communication device associated with the second tank port. In each case, the first and second communication device comprises in particular a transmitter which is able to communicate with a receiver on the gas station side in order to transmit information of the tank system. For example, the first tank connection is set up to transmit the tank volume and / or the level with respect to the first fuel. Accordingly, the second communication device may be configured to transmit tank volume and / or level with respect to the second fuel. If the gas station is equipped with a corresponding communication system, in particular a receiver, this can be used to control the refueling process. In particular, the speed or the speed profile of the refueling can be controlled.

In embodiments of the invention, the vehicle further includes a battery configured to store electrical energy and to supply the stored electrical energy to the electric motor. This may be a so-called traction battery, in particular a high-voltage battery.

In an advantageous embodiment, the vehicle may further comprise an electric charging device for charging the battery with an externally supplied charging current. In such a plug-in version, the fuel cell vehicle thus not only has the option of being supplied and operated with two different fuels, but can also use externally supplied electrical energy as an additional source of energy. As a result, the supply flexibility of the vehicle is further increased.

Advantageously, it can further be provided that the battery is designed to be charged by the fuel cell. In this way, the battery receives a buffer function for storing excess electrical energy of the fuel cell.

In embodiments of the inventions, the tank system further includes a sensor configured to identify the fuel and / or to measure a level. This, especially in embodiments with only a single tank advantageous development, allows the automatic Adaptation of the operating strategy of the fuel cell system depending on the existing fuel.

The first and second fuels are preferably selected from the group consisting of hydrogen, CNG, natural gas, methanol and synthesis gas. Here, hydrogen as the first fuel and CNG as the second fuel are particularly preferable.

The invention further relates to a fuel cell vehicle having the drive train according to the invention.

The various embodiments of the invention mentioned in this application are, unless otherwise stated in the individual case, advantageously combinable with each other.

• 1 ein Blockschaltbild eines Brennstoffzellenfahrzeugs gemäß einer ersten Ausgestaltung der Erfindung;
• 2 ein Blockschaltbild eines Brennstoffzellenfahrzeugs gemäß einer zweiten Ausgestaltung der Erfindung und
• 3 ein Blockschaltbild eines Brennstoffzellenfahrzeugs gemäß einer dritten Ausgestaltung der Erfindung.

The invention will be explained below in embodiments with reference to the accompanying drawings. Show it:

• 1 a block diagram of a fuel cell vehicle according to a first embodiment of the invention;
• 2 a block diagram of a fuel cell vehicle according to a second embodiment of the invention and
• 3 a block diagram of a fuel cell vehicle according to a third embodiment of the invention.

1 shows a fuel cell vehicle generally designated 1 according to a first embodiment of the invention.

The fuel cell vehicle 1 has a fuel cell system 10 with a fuel cell 11 on. Usually, it is the fuel cell 11 to a fuel cell stack of a plurality of stacked and electrically interconnected single cells. The fuel cell system 10 further comprises a control device 12 for controlling the operation of the fuel cell system 10 , The fuel cell system 10 also has a cathode supply, not shown, for the supply and discharge of an oxygen-containing operating gas, in particular air, to and from the cathode chambers of the fuel cell 11 , Furthermore, the fuel cell system has 10 via an anode supply for supplying and discharging a fuel to and from the anode spaces of the fuel cell 11 , Of the anode supply is here just a tank system 20 shown.

The tank system 20 includes a tank 21 that's about a fuel line 27 with the fuel cell 11 connected to provide these with the fuel. The Tank 21 is configured to be refueled with a first fuel, for example hydrogen, and a second fuel, for example CNG. For this purpose, the tank points 21 a first tank connection 23 for refueling with the first fuel and a second tank connection 24 for refueling with the second fuel. The tank connections 23 and 24 are designed as tank neck or tank valves. In order to avoid incorrect refueling, it is customary that the design of the tank connection, in particular its dimensioning, is standardized by convention. This precludes a user from filling a fuel for which the vehicle is not running. For example, the first tank connection 23 a standardized hydrogen tank valve and the second tank connection 24 a standardized CNG tank valve.

The tank system 20 also has a first communication device 25 that is the first tank connection 23 is assigned and via a second communication device 26 that is the second tank connection 24 assigned. The first communication device 25 is set up, a gas station side communication system information regarding the volume of the tank 21 and / or to communicate its level with the first fuel. The second communication device 26 is set up, the gas station side communication system information regarding the size of the tank 21 and / or to communicate its level with the second fuel. For this purpose, the communication facilities 25 . 26 in each case a suitable transmitter, which communicates with a corresponding receiver of the gas station side communication system. It is not necessary that the first and the second communication device 25 . 26 immediately spatially at the respective tank connection 23 . 24 or on the tank 21 are arranged. Rather, they can be anywhere on the vehicle 1 are located. Preferably, however, they are designed so that they by the operation of the corresponding tank connection 23 or 24 be activated by the user for the purpose of refueling to transmit the corresponding data.

The Tank 21 in 1 is also with a sensor 28 equipped, which is capable in the tank 21 identify existing fuel. This is how the sensor works 28 to determine if the tank 21 is filled with the first or the second fuel or a mixture of both. For example, the sensor measures a physical or chemical property of the tank 21 available gas that allows its identification. In addition, the sensor can 28 or another sensor the level of the tank 21 determine, in particular by measuring the pressure inside the tank. The sensor signal of the sensor 28 will have an in 1 interrupted data line to the controller 12 of the fuel cell system 10 transmitted. Thus, it is informed of the type of fuel present and, depending thereon, the operation of the fuel cell system 10 control, for example, the stoichiometry of anode and cathode gas and the operating point of the fuel cell.

This in 1 shown fuel cell vehicle 1 also has a drive train 30 with an electric motor 31 on, which is a drive axle 33 and associated drive wheels 32 for traction of the vehicle 1 drives. The electric motor 31 gets its electrical energy through the fuel cell 11 via a first electrical line 51 ,

The illustrated embodiment according to 1 includes a remote battery 41 by means of a charging connection 42 can be charged via an external power supply. The battery 41 is designed in particular as a traction battery, for example as a PHEV battery (parallel hybrid electro vehicle), so that the electric motor 31 optionally by the fuel cell system 10 or the battery 41 is supplied electrically. For this purpose, the electric motor 31 via a second electrical line 52 with the battery 41 connected. Finally, the system can use a third electrical line 53 which the fuel cell 11 with the battery 41 connects, leaving the battery 41 also by the fuel cell 11 can be loaded. The control of the electrical supply of the electric traction motor 31 through the fuel cell system 10 or battery 41 takes place via an unillustrated hybrid management.

2 shows a fuel cell vehicle according to a second embodiment of the invention. There are elements that comply with the execution of 1 match, denoted by the same reference numerals and will not be explained again in detail.

In the embodiment according to 2 includes the tank system 20 a first tank 21 for receiving the first fuel, in particular hydrogen, wherein the first tank connection 23 the first tank 21 assigned. The tank system 20 also includes a second tank 22 for receiving the second fuel, in particular CNG, wherein the second tank connection 24 the second tank 22 assigned. In this embodiment, the fuel cell 11 optionally with the first tank 21 or with the second tank 22 fluid leading connectable. For this purpose, for example, a controllable valve in the fuel line 27 be arranged (not shown). Alternatively, two separate fuel lines may be the fuel cell 11 with the respective tank 21 and 22 connect. The first tank 21 may further include a first sensor 28 and the second tank 22 with a second sensor 29 be equipped. As in this design, each of the two tanks 21 and 22 However, each can only be refueled with a certain fuel, an identification of the present fuel is not necessary, so that the sensors 28 . 29 can also be omitted. Here are the sensors 28 and 29 be designed as a simple pressure sensors to the levels of the tanks 21 and 22 to determine and to the controller 12 to convey.

3 shows a third embodiment of a fuel cell vehicle according to the invention 1 , Again, matching elements are denoted by the same reference numerals as in the previous figures and will not be explained again.

In contrast to the embodiments according to the 1 and 2 indicates the fuel cell system according to 3 two fuel cells, namely a first fuel cell 11 and a second fuel cell 13 , Every fuel cell 11 and 13 is with an individual control device 12 fitted. In this embodiment, the first fuel cell 11 with the first fuel and the second fuel cell 13 operable with the second fuel. For example, the first fuel cell may be 11 to be a PEMFC or a PAFC, which are operated with pure hydrogen as the first fuel. Furthermore, the second fuel cell may be 13 to be an SOFC operable with CNG or another hydrocarbon. The only tank 21 is in turn with a sensor 28 equipped, which detects the type of refueled fuel and to the control devices 12 transmitted, so that selectively the first or the second fuel cell 11 . 13 to supply the electric motor 31 is operated.

In a modification of the in 3 This system may be similar to this 2 also with two tanks 21 . 22 be equipped with the first tank 21 with the first fuel cell 11 and the second tank 22 with the second fuel cell 13 connected is.

LIST OF REFERENCE NUMBERS

1

fuel cell vehicle

10

The fuel cell system

11

(first) fuel cell

12

control device

13

second fuel cell

20

tank system

21

(first) tank

22

second tank

23

first tank connection

24

second tank connection

25

first communication device

26

second communication device

27

fuel line

28

(first) sensor

29

second sensor

30

drive train

31

Electric motor, traction motor

32

drive wheels

33

drive axle

41

battery

42

charging port

51

first electrical line

52

second electrical line

53

third electrical line

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102008032105 A1 [0006]
• DE 102004037851 A1 [0007]

Claims (10)

Drive train for a fuel cell vehicle (1) comprising an electric motor (31) for driving the vehicle (1), a fuel cell system (10) for generating electrical energy for operating the electric motor (31) having at least one fuel cell (11) and which is set up to be selectively operated with a first fuel or a second fuel, and a tank system (20) having a first tank port (23) for refueling with the first fuel and a second tank port (24) for refueling with the second fuel. Drive train after Claim 1 wherein the tank system (20) includes a tank (21) for selectively receiving the first and second fuels, and the first and second tank ports (23, 24) are associated with the tank (21). Drive train after Claim 1 wherein the tank system (20) has a first tank (21) for receiving the first fuel and the first tank connection (23) is associated with the first tank (21) and has a second tank (22) for receiving the second fuel and the second Tank connection (24) is associated with the second tank (22). Drive train according to one of the preceding claims, wherein the fuel cell system (10) has a first fuel cell operable with the first fuel cell (11) and a second with the second fuel fuel cell (13). Drive train after Claim 4 wherein the tank system (20) comprises a tank (21) for selectively receiving the first or second fuel and the first and second tank ports (23, 24) associated with the tank (21) and the tank (21) optionally with the first or the second fuel cell (11, 13) is fluid-conductively connectable. Drive train according to one of the preceding claims, further comprising a first communication means (25) associated with the first tank port (23) and a second communication means (26) associated with the second tank port (24). A power train according to any one of the preceding claims, further comprising a battery (41) arranged to store electrical energy and to supply stored electrical energy to the electric motor (31). Drive train after Claim 7 further comprising an electrical charging device (42) for charging the battery (41) with an externally supplied charging current. A power train according to any one of the preceding claims, wherein the tank system (20) further comprises a sensor (28) arranged to identify the fuel and / or to measure a level. Vehicle (1) with a drive train according to one of Claims 1 to 9 ,

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